WASHINGTON — American officials in recent days have warned repeatedly that the release of documents by WikiLeaks could put people's lives in danger.

But despite similar warnings ahead of the previous two massive releases of classified U.S. intelligence reports by the website, U.S. officials concede that they have no evidence to date that the documents led to anyone's death.

Before Sunday's release, news organizations given access to the documents and WikiLeaks took the greatest care to date to ensure no one would be put in danger. In statements accompanying stories about the documents, several newspapers said they voluntarily withheld information and that they cooperated with the State Department and the Obama administration to ensure nothing released could endanger lives or national security.

The newspapers "established lists in common of people to protect, notably in countries ruled by dictators, controlled by criminals or at war," according to an account by Le Monde, a French newspaper that was among the five news organizations that were given access to the documents. "All the identities of people the journalists believed would be threatened were redacted," the newspaper said in what would be an unprecedented act of self censorship by journalists toward government documents.

The newspapers also communicated U.S. government concerns to WikiLeaks to ensure sensitive data didn't appear on the organization's website.

"After its own redactions, The (New York) Times sent Obama administration officials the cables it planned to post and invited them to challenge publication of any information that, in the official view, would harm the national interest," The New York Times said in a story published on its website Sunday. "After reviewing the cables, the officials — while making clear they condemn the publication of secret material — suggested additional redactions. The Times agreed to some, but not all."

The paper said it also passed the government's concerns to WikiLeaks "at the suggestion of the State Department."

Unlike the release earlier this year of intelligence documents about the war in Afghanistan, when WikiLeaks posted on its website unredacted documents that included the names of Afghan informants, WikiLeaks agreed this time not to release more than 250,000 documents because they hadn't been vetted by the U.S. government.

The newspapers said WikiLeaks had agreed to release only the documents used in preparation for articles that appeared in the five publications, which in addition to Le Monde and The New York Times included Great Britain's Guardian, Germany's Der Spiegel and Spain's El Pais.

"Together, the five newspapers have carefully edited the raw text used to remove all names and indices whose disclosure could pose risks to individuals," Le Monde said.

Le Monde also said U.S. officials would have the opportunity to argue their point of view in its columns.

Sunday's release showed a growing willingness on the part of WikiLeaks, whose founder, Julian Assange, is facing rape allegations in Sweden, to cooperate with the government on the document trove.

When the first batch of documents was released this summer, WikiLeaks unapologetically released the names of Afghan informants, which U.S. officials charged could lead to their deaths. In the second batch, released in October, which focused on the Iraq war, WikiLeaks withheld names but didn't work with the U.S. government to determine what could endanger U.S. national security.

Pentagon spokesman Geoff Morrell has said previously that there was no evidence that anyone had been killed because of the leaks. Sunday, another Pentagon official told McClatchy that the military still has no evidence that the leaks have led to any deaths. The official didn't want to be named because of the issue's sensitivity.

"We have yet to see any harm come to anyone in Afghanistan that we can directly tie to exposure in the WikiLeaks documents," Morrell told the Washington Post on Aug 11. But "there is in all likelihood a lag between exposure of these documents and jeopardy in the field."

Despite that, the government has maintained that the release of the documents could put people in grave danger. In a letter to WikiLeaks Saturday, the State Department's legal adviser, Harold Koh, said that the release "could place at risk the lives of countless innocent individuals — from journalists to human rights activists and bloggers to soldiers to individuals providing information to further peace and security."

"Despite your stated desire to protect those lives, you have done the opposite and endangered the lives of countless individuals. You have undermined your stated objective by disseminating this material widely, without redaction, and without regard to the security and sanctity of the lives your actions endanger," Koh said.

It wasn't immediately clear how Sunday's release would endanger secret U.S. programs, though it wasn't difficult to conclude that some of the releases could endanger local officials' political futures.

One cable, for example, describes a meeting between Gen. David Petraeus, then the commander of U.S. Central Command, and Yemen's president where they were discussing what was apparently a U.S. bombing campaign against al Qaida in the Arabian Peninsula. According to the cable, Yemeni President Ali Abdullah Saleh began to "joke that he had just 'lied' by telling his Parliament that the Yemeni forces were responsible for attacks carried out by the U.S.

"We'll continue saying the bombs are ours, not yours," the cable quotes Saleh as saying.

CORRECTION: An earlier version of this story incorrectly stated in the 12th paragraph that Assange is facing rape charges. No charges have been filed against him in Sweden.